public void CloudFileShareCreateIfNotExistsAPM()
        {
            CloudFileShare share = GetRandomShareReference();

            try
            {
                using (AutoResetEvent waitHandle = new AutoResetEvent(false))
                {
                    IAsyncResult result = share.BeginCreateIfNotExists(
                        ar => waitHandle.Set(),
                        null);
                    waitHandle.WaitOne();
                    Assert.IsTrue(share.EndCreateIfNotExists(result));
                    result = share.BeginCreateIfNotExists(
                        ar => waitHandle.Set(),
                        null);
                    waitHandle.WaitOne();
                    Assert.IsFalse(share.EndCreateIfNotExists(result));
                }
            }
            finally
            {
                share.DeleteIfExists();
            }
        }